Curious title, Tomorrow in the Battle. It’s a phrase from Richard III (Act V, scene 3), the partial title of a well-reviewed 1994 novel by Spanish writer Javier Marías, and apparently the English translation of a German war cry. And what it has to do with what’s happening on Ars Nova’s stage, heaven knows. At any rate, to enjoy Kieron Barry’s drama, you’d better love London: there’s a lot of it here. And you’d better have a tolerance for shaky British accents. Patrick Hamilton, as our not-altogether-heroic hero, can’t decide whether to pronounce it “again” or “a gain”; he keeps going back and forth. And Ruth Sullivan and Allison Threadgold, as the women in his life, flatten or broaden their vowels as they see fit, not always consistently.